1. Field of the Invention
The present invention relates generally to a lock, and more particularly to a lock, which the lock still has function of burglarproof while the core is turning.
2. Description of the Related Art
A conventional lock used in a door or a draw of a cupboard has multi-section of lock. User has to turn the key for 720 degrees or more to unlock the lock. Such lock has a poor capacity of burglarproof. If the thief can turn the core of such lock by a specific tool, it is sure to turn the core continuously until the lock is unlocked. In other words, if the thief breaks the first section of lock of the conventional lock, the second and the third section of lock are released at the same time.
The primary objective of the present invention is to provide a lock, which has a superior function of burglarproof.
The secondary objective of the present invention is to provide a lock, which the lock still has function of burglarproof while the core is turned by a key tool.
According to the objectives of the present invention, a lock comprises an outer housing, which is open at an end thereof and is closed at the other end thereof, having an outer slot at an interior side thereof and a key bore at the closed end thereof. An inner housing is received in the outer housing for rotation between a predetermined angle, wherein the inner housing has an inner slot, which is open at both an interior side and an exterior side thereof, and a driving section. A plurality of locking plates are received in the inner housing in sequence and rotated between a predetermined angle, each of which has a key bore at a center thereof and a recess at a periphery thereof. A movable pin has a predetermined length to be moved between two positions in which the movable pin is received either in the inner slot of the inner housing and the outer slot of the outer housing or in the inner slot of the inner housing and the recesses of the locking plates. The inner housing is reciprocated in the outer housing between a first position and a second position and has an annular slot and a position slot, which is communicated with the annular slot, at the exterior side thereof. A first tumbler pin is provided at the outer housing and has an inner end thereof received either in the annular slot or in the position slot of the inner housing. The position pin is moved to the position slot of the inner housing to restrain the inner housing from rotation while the inner housing is moved to the first position and the position pin is moved to the annular slot of the inner housing to release the inner housing for free rotation while the inner housing is moved to the second position.